Patients receiving oxygen for therapeutic purposes are typically fitted with an oxygen mask or cannula which receives the oxygen from a pressurized tank. Since the pressure of the oxygen within the tank can be at about 2200 psi, the pressure of the oxygen delivered to the patient is reduced to a low pressure, for example, about 22 psi, by a gas regulator. Some gas regulators have a pressure regulator for reducing the pressure of the oxygen as well as a flow meter for adjusting the flow rate of the gas. For certain applications, for example, patients who transport a portable oxygen tank with them as they conduct their daily activities, it is desirable for the size of the gas regulator to be minimized. However, some previous designs of gas regulators have been larger than preferred, or include parts that are complex and expensive to manufacture.